1 45
Distance measuring equipment DME distance (nm)
(d) Electronic instrument-DME display (a) Self-contained D M E displays
Figure 1 1 .5 Various types of DME display
11.5
En route navigation using radio navigation aids
(b) D M E panel/transceiver for general aviation
Basic en route navigation guidance for commercial aircraft can be readily accomplished using co-located VOR and DME systems, thereby providing rho-theta fixes from a single navigation aid. The DME frequency is paired with the VOR frequency; this means that only the VOR frequency needs to be tuned, the DME frequency is automatically tuned as a result. Alternatively, rho-rho fixes can be established from a pair of DME navigation aids. Note that this produces an ambiguous fix unless another DME is used, see Figure 1 1 .6. An example of DME transponder locations and co-located VOR DME navigation aids in Switzerland is provided in Table 1 1 .2.
/
/
/
/
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. ..... - · - · · -
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DME 1
I
I · ·-_:_I
.
.,.. ,.,.
(c) Radio distance magnetic ind icator (RDMI)
DME 2 · -
I
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I
I
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·.
......
Figure 1 1 .6 Ambiguous DME-DME position
